Once the tour kicked off in earnest on May 5 in the Netherlands, AC/DC played a 20-song set that featured nine songs from the Scott era and 11 from Johnson's time with the group, including five tracks from their 1980 masterpiece Back in Black and three from their most recent album, 2014's Rock or Bust.

In early February 2016, they dropped the new album's first single, "Play Ball," from the set in favor of the LP track "Got Some Rock & Roll Thunder," and traded "Baptism by Fire" for yet another Back in Black song, "Given the Dog a Bone."

Johnson's hearing problems forced the band off the road at the end of February 2016, postponing the 10 shows still remaining on the U.S. leg of the tour. On May 7, the group returned to the road for previously scheduled dates in Europe with Guns N' Roses frontman Rose temporarily helping out. They kept the entire set list from the Johnson-fronted leg of the tour, and immediately added two more songs from the Scott years, "Rock and Roll Damnation" and "Riff Raff."

The Rock or Bust world tour -- which as you can see from the gallery below has been quite chaotic -- concludes Sept. 20 in Philadelphia. Bassist Cliff Williams has said he will retire after that show, leaving Young as the last remaining member of AC/DC's 1994-2014 lineup. The guitarist has said he doesn't know what the future holds for the group.